This information is containing in a short report you can find here and summarised here. Along with the warmest 12 months, a host of other records have also been broken in individual towns and cities and right across the nation. Because Australia is so big it takes a massive buildup of heat to break countrywide records, some of the most important I've taken from the report and shown below.
"The last 12 months saw a large number of temperature records set across Australia, including:
- Australia’s hottest summer day on record (7 January)
- Australia’s warmest winter day on record (31 August)
- Australia’s warmest month on record (January)
- Australia’s warmest summer on record
- Australia’s warmest January to August period on record
- Australia’s warmest 12 month period on record"
Overall the last year has seen temperatures 1.11 ̊C above average. While that may not sound like all that much, across a whole country, for a whole year, this gives us weather that's noticeably hotter.
Since the first half of the 20th century (1900-1950) temperatures across Australia have risen by ~0.75 ̊C and between now and 2050 are likely to rise by another 2 ̊C or more. This mean's that by 2050 the temperatures we have had over this past year (including the record breaking summer heat) would by then be a much colder than average year. A normal year would be a least a degree hotter than the past 12 months and a record breaking year could see temperature anomalies 3 or 4 times greater than experienced over the past year. Something to think about as Australia goes about dismantling all its policies to combat global warming.